Question : Monitoring Xen VPS's

I'm running several VPS on 3 physical  Xen  (debian) servers. My question is:

1. How can I monitor Xen dom0 server?

2. How can I monitor (web base) CPU, memory, load, disk/partitions use of every VPS from a central point?

3. Is it possible to VPS's users to access via web their virtual machine monitoring and statistics?

Answer : Monitoring Xen VPS's

>1. How can I monitor Xen dom0 server?
you do it in the same way you would do with a real machine: login via ssh and check with the default utilities (procfs, top, dstat, etcetcetc); or you can install and configure Nagios on that srver, so that you can see it by web

>2. How can I monitor (web base) CPU, memory, load, disk/partitions use of every VPS from a central point?
you can publish all the Nagios organized in a single website, so that you can easily browse

>3. Is it possible to VPS's users to access via web their virtual machine monitoring and statistics?
uhm, look here http://www.novell.com/coolsolutions/feature/19490.html